High levels of antibiotic resistant bacteria in UK rivers prompts regulatory concerns

The level of antibiotic resistant bacteria found near intensive farms has sparked concerns about public health and water monitoring practices.

Researchers at the Bureau of Investigative Journalism, with the World Animal Protection and the Alliance to Save Our Antibiotics, tested water and sediment samples both upstream and downstream of twelve poultry and pig farms in the Wye Valley and in Norfolk, eight of which were intensive. They also analysed slurry waste at four cattle farms, all of which were intensive, and one sample of poultry litter in Sussex.

Sulfonamides, which are a group of antibiotics used to treat bacterial infections such as urinary tract infections or pneumonia, were discovered in higher quantities downstream of the pig and chicken farms, according to the analysis of the samples by the Fera laboratory in York. The researchers concluded that this suggests antimicrobial resistance (AMR) is entering the environment from these farms.

Signs of AMR were seen at higher levels downstream in waterways near five of the intensive farms than in waterways upstream. Tests from the four free-range or organic farms showed no difference between upstream or downstream levels of AMR. These results suggest more intensive farms may result in higher levels of AMR entering waterways than at free range farms.

In the UK, sulfonamides are more widely used in farm animals than in human medicine, the research has prompted concerns that overuse in livestock could see AMR occur in humans too after being impacted by the strains in waterways.

Sulfonamide-resistant genes were discovered in all the cattle waste samples and the poultry litter tested by the researchers, the poultry litter sample and one cattle waste sample also contained antibiotic resistant E coli.

The researchers also found that river water in the Wye valley contained a version of MRSA, a bacteria that is resistant to many antibiotics and is frequently referred to as a “superbug”, and residues of ionophore antibiotics, which are widely used in the chicken industry.

The poor ecological condition of the river Wye, due to farming practices, has made headlines in recent years.

Amongst other worrying finds noted by the investigators were E coli resistant to cefotaxim and S aureus resistant to vancomycin, both drugs classified by the World Health Organization (WHO) as critically important in human medicine.

Cóilín Nunan, the scientific advisor to the Alliance to Save our Antibiotics, told the Bureau: “The use of antibiotics related to cefotaxime is finally being reduced in farming, but far greater reductions are needed and this will only be achieved through government action.”

Chairman of the environmental audit committee Philip Dunne also told the Bureau: “This investigation raises the risk in our rivers from emerging antimicrobial resistance. This is another good reason why water quality monitoring needs to be ramped up to avoid people becoming gravely ill.”

The UK currently does not legislate on the spread of antibiotic resistance through farm waste disposal. This year, a ban on the routine use of antibiotics came into effect across the European Union (EU), as well as a restriction on preventative use to only the exceptional treatments of individual animals.

A spokesperson from DEFRA said: “We do not support routine preventative use of antibiotics in animals — they should not compensate for poor husbandry practices. We will continue to look into strengthening legislation in this area.”

This comes as DEFRA announced today that farmers in England will soon be able to apply for grants of up to £250,000 to improve their slurry storage in order to “tackle water and air pollution”.

The release from DEFRA also cited that around half of slurry stores in England are not fit-for-purpose, forcing farmers to spread slurry when there is no crop need.